PolishStemFilter.java

/**   
 * License Agreement for OpenSearchServer
 *
 * Copyright (C) 2013 Emmanuel Keller / Jaeksoft
 * 
 * http://www.open-search-server.com
 * 
 * This file is part of OpenSearchServer.
 *
 * OpenSearchServer is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 * OpenSearchServer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with OpenSearchServer. 
 *  If not, see <http://www.gnu.org/licenses/>.
 **/

package com.jaeksoft.searchlib.analysis.filter;

import java.io.IOException;

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.pl.PolishAnalyzer;
import org.apache.lucene.analysis.stempel.StempelFilter;
import org.apache.lucene.analysis.stempel.StempelStemmer;
import org.egothor.stemmer.Trie;

import com.jaeksoft.searchlib.SearchLibException;
import com.jaeksoft.searchlib.analysis.ClassPropertyEnum;
import com.jaeksoft.searchlib.analysis.FilterFactory;

public class PolishStemFilter extends FilterFactory {

	static final Trie stemTable;

	static {
		try {
			stemTable = StempelStemmer.load(PolishAnalyzer.class
					.getResourceAsStream(PolishAnalyzer.DEFAULT_STEMMER_FILE));
		} catch (IOException e) {
			throw new RuntimeException("Unable to load Polish stem table", e);
		}
	}

	private int minLength;

	@Override
	public void initProperties() throws SearchLibException {
		super.initProperties();
		addProperty(ClassPropertyEnum.MIN_LENGTH, "3", null, 10, 1);
	}

	@Override
	public void checkValue(ClassPropertyEnum prop, String value)
			throws SearchLibException {
		if (prop == ClassPropertyEnum.MIN_LENGTH)
			minLength = Integer.parseInt(value);
	}

	@Override
	public TokenStream create(TokenStream tokenStream) {
		return new StempelFilter(tokenStream, new StempelStemmer(stemTable),
				minLength);
	}

}